阅读说明：本技术 热交换机组 (Heat exchanger unit ) 是由 小林俊幸 桃野俊之 于 2019-09-24 设计创作，主要内容包括：在利用可燃性制冷剂的热交换机组中,提供一种能够进行可靠性高的制冷剂泄漏检测的热交换机组。热交换机组通过使向利用侧设备输送的液体介质与可燃性的制冷剂进行热交换,进行液体介质的冷却和加热中的至少一者。热交换机组包括热交换器、外壳、配置于外壳的下部且配置于热交换器的下方的集水盘(80)、气体检测传感器(70)。在热交换器中,在制冷剂与液体介质之间进行热交换。外壳收纳热交换器。集水盘具有底板(82)以及从底板向上方延伸的侧壁(84)。第一气体检测传感器对处于集水盘的底板的上方且处于集水盘的侧壁的上端部的下方的集水盘的内部空间(Si)是否存在制冷剂的气体进行检测。(Provided is a heat exchange unit using a combustible refrigerant, wherein the heat exchange unit can detect leakage of the refrigerant with high reliability. The heat exchanger unit performs at least one of cooling and heating of the liquid medium by exchanging heat between the liquid medium sent to the use-side device and the flammable refrigerant. The heat exchanger unit comprises a heat exchanger, a shell, a water collecting tray (80) arranged at the lower part of the shell and below the heat exchanger, and a gas detection sensor (70). In the heat exchanger, heat is exchanged between the refrigerant and the liquid medium. The housing houses the heat exchanger. The water collection tray has a bottom plate (82) and a side wall (84) extending upward from the bottom plate. The first gas detection sensor detects whether gas of the refrigerant exists in an internal space (Si) of the water collection tray above a bottom plate of the water collection tray and below an upper end portion of a side wall of the water collection tray.)

1. A heat exchanger unit (100, 200) that performs at least one of cooling and heating of a liquid medium sent to a utilization-side device (410) by exchanging heat between the liquid medium and a flammable refrigerant, the heat exchanger unit comprising:

a heat exchanger (10, 110) that exchanges heat between the refrigerant and the liquid medium;

a housing (90, 190) that houses the heat exchanger;

a water collection tray (80) having a bottom plate (82) and a side wall (84) extending upward from the bottom plate, the water collection tray being disposed at a lower portion of the housing and below the heat exchanger; and

a first gas detection sensor (70) that detects whether gas of the refrigerant is present in an interior space (Si) of the water collection tray above the bottom plate of the water collection tray and below an upper end of the side wall of the water collection tray.

2. Heat exchanger unit according to claim 1,

the first gas detection sensor has a first detection element (72) disposed in the internal space of the water collection tray, and detects whether or not the gas of the refrigerant is present at a location where the first detection element is disposed.

3. Heat exchanger unit according to claim 2,

the bottom plate of the water collecting tray has an inclined portion (82a) inclined with respect to a horizontal plane,

the first detection element is disposed on the lower end (82ab) side of the inclined portion.

4. Heat exchanger unit according to claim 2 or 3,

at least one of the bottom plate and the side wall of the water collection tray is provided with a drain opening (86a) for draining water of the inner space of the water collection tray,

the first detection element is disposed near the drain opening.

5. Heat exchanger unit according to any of claims 2 to 4,

the heat exchanger unit further comprises a float (88) arranged in the inner space of the water collection tray,

the first detecting element is attached to an upper surface (88a) or a side surface (88b) of the float.

6. Heat exchanger unit according to any of claims 2 to 5,

the heat exchanger unit further includes a second gas detection sensor (270) having a second detection element (272) disposed outside the housing, the second gas detection sensor detecting whether or not the gas of the refrigerant is present at a location where the second detection element is disposed.

7. Heat exchanger unit according to any of claims 2 to 6,

the housing is formed with opening portions (91b, 191b) for maintenance,

the first detection element is disposed in a space near the opening.

8. Heat exchanger unit according to any of claims 2 to 7,

the heat exchanger unit further comprising a pump (60), the pump (60) being arranged inside the housing (90) and feeding the liquid medium to the utilization-side device,

the interior of the casing is divided into at least a pump arrangement region (A1) in which the pump is arranged and a refrigerant side region (A2) in which refrigerant piping for flowing the refrigerant or the heat exchanger is arranged in a plan view,

the first detection element is disposed in the vicinity of the refrigerant-side region away from the pump disposition region in a plan view.

Technical Field

The present disclosure relates to a heat exchanger unit that cools and heats a liquid medium by exchanging heat between the liquid medium and a refrigerant, the liquid medium being sent to a user-side device.

Background

Conventionally, a heat exchanger unit is known that cools and heats a liquid medium by exchanging heat between the liquid medium sent to a user-side device and a refrigerant. For example, patent document 1 (international publication No. 2014/97440) discloses a heat exchanger unit in which brine or the like is cooled by a refrigerant in a heat exchanger disposed in a relay unit, and the cooled brine or the like is sent to a user-side device.

Disclosure of Invention

Technical problem to be solved by the invention

However, in the heat exchanger unit, flammable (including slightly flammable) refrigerant may be used in consideration of various characteristics of the refrigerant. However, when flammable refrigerant is used in the heat exchanger unit, if the refrigerant leaks for some reason, fire may be caused.

Therefore, in a heat exchange unit using a flammable refrigerant, highly reliable refrigerant leakage detection is desired.

Technical scheme for solving technical problem

The heat exchanger unit according to the first aspect performs at least one of cooling and heating of the liquid medium by exchanging heat between the liquid medium sent to the use-side device and the flammable refrigerant. The heat exchanger package includes a heat exchanger, a housing, a water collection tray, and a first gas detection sensor. In the heat exchanger, heat is exchanged between the refrigerant and the liquid medium. The housing houses the heat exchanger. The water collecting tray is arranged at the lower part of the shell and below the heat exchanger. The water collection tray has a bottom plate and a side wall extending upward from the bottom plate. The first gas detection sensor detects whether gas of the refrigerant is present in an internal space of the water collection tray above a bottom plate of the water collection tray and below an upper end portion of a side wall of the water collection tray.

Generally, the refrigerant gas is heavier than air, and when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in the present heat exchanger unit, the leaked refrigerant gas is likely to accumulate in the water collecting tray disposed at the lower portion of the casing and receiving the dew condensation water and the like generated in the piping, the heat exchanger and the like.

Here, by detecting whether or not the refrigerant gas is present in the internal space of the water collection tray in which the leaked refrigerant gas is likely to accumulate, it is possible to perform the leakage detection of the refrigerant gas with high reliability.

In the heat exchanger unit according to the second aspect, the first gas detection sensor includes a first detection element disposed in the internal space of the water collection tray, and detects whether or not the refrigerant gas is present at a location where the first detection element is disposed.

Here, by disposing the detection element of the first gas detection sensor in the internal space of the water collection tray in which the leaked refrigerant is likely to accumulate, it is possible to perform refrigerant leakage detection with high reliability.

In the heat exchanger unit according to a third aspect, the bottom plate of the water collection tray has an inclined portion inclined with respect to a horizontal plane. The first detection element is arranged on one side of the lower end of the inclined part.

Here, since the detection element of the first gas detection sensor is disposed on the lower end side of the inclined portion where refrigerant gas is likely to collect, refrigerant leakage detection with high reliability can be performed.

In the heat exchanger unit according to a fourth aspect, in addition to the heat exchanger unit according to the second or third aspect, at least one of the bottom plate and the side wall of the water collection tray is provided with a drain port for draining water from the internal space of the water collection tray. The first detection element is arranged near the water outlet.

Here, since the detection element of the first gas detection sensor is disposed in the vicinity of the drain port of the water collection tray disposed at a position where water is easily discharged, refrigerant leakage detection with high reliability can be performed.

The heat exchanger unit according to a fifth aspect of the present invention is the heat exchanger unit according to any one of the second to fourth aspects, further comprising a float disposed in an inner space of the water collection tray. The first detecting member is mounted on an upper surface or a side surface of the float.

Here, since the detection element of the first gas detection sensor is attached to the upper surface or the side surface of the float, the refrigerant leakage can be detected even in a state where water is accumulated in the water collection tray.

The heat exchanger unit according to a sixth aspect is the heat exchanger unit according to any one of the second to fifth aspects, further comprising a second gas detection sensor. The second gas detection sensor has a second detection element disposed outside the housing. The second gas detection sensor detects whether or not the gas of the refrigerant is present at the location where the second detection element is disposed.

Here, even when the refrigerant gas flows out of the housing, the refrigerant gas can be detected by the second gas detection sensor provided separately, and safety is high.

The heat exchanger unit according to a seventh aspect is the heat exchanger unit according to any one of the second to sixth aspects, wherein the housing has an opening for maintenance. The first detection element is disposed in a space near the opening.

Here, since the detection element of the first gas detection sensor is disposed in the space near the opening for maintenance, the detection element of the first gas detection sensor can be easily inspected and replaced.

The heat exchanger unit according to an eighth aspect of the present invention is the heat exchanger unit according to any one of the second to seventh aspects, further comprising a pump. The pump is disposed inside the housing. The pump conveys the liquid medium to the utilization-side apparatus. The interior of the housing is divided into at least a pump arrangement region and a refrigerant side region in a plan view. The pump configuration area is for the pump configuration. The refrigerant side region is provided with refrigerant pipes or heat exchangers for flowing the refrigerant. The first detection element is disposed in the vicinity of the refrigerant-side region away from the pump disposition region in a plan view.

Here, since the detection element of the first gas detection sensor is disposed inside the housing at a position relatively close to the refrigerant pipe or the heat exchanger through which the refrigerant flows, refrigerant leakage detection with high reliability can be performed.

Drawings

Fig. 1 is a perspective view of a heat exchanger unit of a first embodiment.

Fig. 2 is a schematic block diagram of a thermal load handling system including the heat exchanger unit of fig. 1.

Fig. 3 is a schematic plan view of a machine room as an installation place of the heat exchanger unit of fig. 1.

Fig. 4 is a schematic front view of the heat exchanger unit of fig. 1.

Fig. 5 is a schematic plan view of a lower section of the interior of the housing of the heat exchanger unit of fig. 1.

Fig. 6 is a schematic front view of the heat exchanger unit of fig. 1 with a side plate of a housing removed.

Fig. 7 is a schematic right side view of the heat exchanger unit of fig. 1 with a side plate of the housing removed.

Fig. 8 is a schematic top view of a water collection tray of the heat exchanger unit of fig. 1.

Fig. 9 is a diagrammatic rear view of a portion of the housing of the heat exchanger package of fig. 1 and the water collection tray of fig. 8.

Fig. 10 is a schematic right side view of the water collection tray of fig. 8.

Fig. 11A is a view schematically illustrating an example of a float provided in the inner space of the water collection tray of fig. 8.

Fig. 11B is a view schematically depicting another example of the float provided to the inner space of the water collecting tray of fig. 8.

Fig. 12 is a schematic front view of a heat exchanger unit according to modification 1B.

Fig. 13 is a perspective view of a heat exchanger unit of the second embodiment.

Fig. 14 is a schematic configuration diagram of a heat load processing system including the heat exchanger unit of fig. 13.

Fig. 15 is a schematic plan view of a lower section of the interior of the housing of the heat exchanger unit of fig. 13.

Fig. 16 is a schematic front view of the heat exchanger unit of fig. 13 with a side plate of a housing removed.

Fig. 17 is a schematic right side view of the heat exchanger unit of fig. 13 with a side plate of the housing removed.

Fig. 18 is a schematic rear view of a portion of the housing of the heat exchanger unit of fig. 12 and a water collection tray of the heat exchanger unit of fig. 12.

Fig. 19 is a specific example of the refrigerant used in the heat exchanger unit according to the first and second embodiments.

Detailed Description

Next, an embodiment of the heat exchanger unit will be explained.

< first embodiment >

(1) Integral structure

A heat exchanger unit 100 and a heat load processing system 1 including the heat exchanger unit 100 according to a first embodiment will be described with reference to the drawings.

Fig. 1 is a perspective view of a heat exchanger package 100. Fig. 2 is a schematic configuration diagram of the heat load processing system 1 including the heat exchanger unit 100. In fig. 2, only one of the four heat source units 300 is depicted, and the other three are omitted. Fig. 3 is a schematic plan view of the machine room R in which the heat exchanger unit 100 is installed. Fig. 4 is a schematic front view of the heat exchanger unit 100. Fig. 5 is a schematic plan view of a lower section inside the casing 90 of the heat exchanger unit 100. Fig. 6 is a schematic front view of the heat exchanger unit 100 in a state where a side plate of the casing 90 is removed. Fig. 7 is a schematic right side view of the heat exchanger unit 100 with a side plate of the casing 90 removed.

In the following description, expressions indicating directions such as "up", "down", "left", "right", "front (front)", "rear (back)" and the like are sometimes used. These directions represent the directions indicated by arrows in the drawings, unless otherwise specified.

The heat load processing system 1 mainly includes a heat exchanger unit 100, a heat source unit 300, and a utilization-side device 410.

The heat exchanger unit 100 is a unit that performs at least one of cooling and heating of a liquid medium by exchanging heat between the liquid medium and a refrigerant. In particular, the heat exchange unit 100 of the present embodiment performs both cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant. The liquid medium cooled or heated by the liquid refrigerant in the heat exchange unit 100 is sent to the utilization-side device 410.

The liquid medium used in the present embodiment is, for example, a heat medium such as water or brine (brine). The liquid medium used as the brine is, for example, an aqueous sodium chloride solution, an aqueous calcium chloride solution, an aqueous ethylene glycol solution, an aqueous propylene alcohol solution, or the like. The liquid medium is not limited to the kind exemplified herein, and may be appropriately selected. In the present embodiment, brine is used as the liquid medium.

In the present embodiment, the refrigerant is a flammable refrigerant. In addition, flammable refrigerants herein include refrigerants that conform to class 3 (strong flammability), class 2 (weak flammability), subclass 2L (slight flammability) under the ASHRAE34 refrigerant designation and safety classification standard or ISO817 refrigerant designation and safety classification standard in the united states. For example, fig. 19 shows a specific example of the refrigerant used in the present embodiment. In fig. 19, "ASHRAE number" is an ASHRAE number of a refrigerant specified in ISO817, "component" indicates an ASHRAE number of a substance contained in the refrigerant, "mass%" indicates a mass percentage concentration of each substance contained in the refrigerant, and "substitute" indicates a substance name of a refrigerant that is frequently substituted by the refrigerant. The refrigerant used in the present embodiment is R32. In addition, the refrigerant illustrated in fig. 19 has a characteristic of having a density greater than that of air.

The installation place of the heat exchanger unit 100 is not limited, and it is installed indoors, for example. In the present embodiment, the heat exchanger unit 100 is provided in the machine room R together with other devices (devices OD1 to OD3 in fig. 3) as shown in fig. 3. The devices OD1 to OD3 include, but are not limited to, a boiler, a generator, a switchboard, and the like. However, only the heat exchanger unit 100 may be provided in the machine room R. The heat exchanger unit 100 may be installed outdoors, such as on the roof of a building or around the building.

The heat source unit 300 is a device that cools or heats a refrigerant using air as a heat source. The heat source unit 300 is connected to the heat exchanger unit 100 through the liquid refrigerant communication tube 52 and the gas refrigerant communication tube 54, and constitutes the refrigerant circuit 50 together with the heat exchanger unit 100. The refrigerant circuit 50 mainly includes a compressor 330 of a heat source unit 300 described later, a flow path switching mechanism 332, a heat source side heat exchanger 340, a second expansion mechanism 344, a use side heat exchanger 10 and a first expansion mechanism 20 of a heat exchanger unit 100 described later, and the like. The place where the heat source unit 300 is installed is not limited, and the heat source unit may be installed on a roof, around a building, or the like.

In the present embodiment, the heat load processing system 1 includes four heat source units 300 (see fig. 2). The heat exchanger unit 100 cools/heats the liquid medium by the refrigerant cooled/heated in the four heat source units 300. However, the number of heat source units 300 is an example, and the number is not limited to four. The number of the heat source units 300 may be one to three, or five or more.

The utilization-side device 410 is a device that utilizes or stores the liquid medium cooled/heated in the heat exchanger group 100. The use-side equipment 410 is connected to the heat exchanger unit 100 via a liquid medium communication pipe 420, and constitutes a liquid medium circuit 400. The liquid medium fed by the pump 60 of the heat exchanger unit 100 described later is circulated in the liquid medium circuit 400.

The use-side device 410 is, for example, an air handling unit or a fan coil unit that performs air conditioning by exchanging heat between the liquid medium cooled and heated in the heat exchanger unit 100 and air. However, the use-side facility 410 may be a manufacturing facility that cools and heats a manufacturing apparatus or a product using a liquid medium cooled and heated in the heat exchange unit 100. The utilization-side device 410 may be a container that stores the liquid medium cooled/heated in the heat exchanger unit 100. The liquid medium stored in the container serving as the use-side device 410 is transferred to a device using the liquid medium by, for example, a pump not shown.

Only one utilization-side device 410 is illustrated in fig. 2. However, the heat load processing system 1 may include a plurality of user-side devices, and the liquid medium cooled/heated in the heat exchanger group 100 may be sent to the plurality of user-side devices. When the heat load processing system 1 includes a plurality of utilization-side devices, the types of the utilization-side devices may be completely the same, or the utilization-side devices may include a plurality of types of devices.

(2) Detailed structure

The heat source unit 300, the liquid refrigerant communication tube 52, the gas refrigerant communication tube 54, the liquid medium circuit 400, and the heat exchanger unit 100 will be described in detail.

(2-1) Heat Source side Unit

The heat source unit 300 will be described with reference to fig. 2. In fig. 2, only one of the four heat source units 300 is depicted, and the other three are omitted. The heat source unit 300, which is not depicted, also has the same structure as the heat source unit 300 described below.

The heat source unit 300 mainly includes an in-unit refrigerant pipe 350, a compressor 330, a flow path switching mechanism 332, a heat source side heat exchanger 340, a second expansion mechanism 344, a fan 342, a gas side stop valve 304, a liquid side stop valve 302, and a heat source side control board 395 (see fig. 2).

(2-1-1) piping inside Unit

The in-unit refrigerant pipe 350 is a pipe connecting the components of the heat source unit 300 including the compressor 330, the flow path switching mechanism 332, the heat source-side heat exchanger 340, the second expansion mechanism 344, the gas-side stop valve 304, and the liquid-side stop valve 302. The in-unit refrigerant pipe 350 includes a suction pipe 351, a discharge pipe 352, a first gas-side pipe 353, a liquid-side pipe 354, and a second gas-side pipe 355 (see fig. 2).

The suction pipe 351 is a pipe connecting a suction port (not shown) of the compressor 330 and the flow path switching mechanism 332. The suction pipe 351 is provided with a not-shown reservoir. The discharge pipe 352 is a pipe connecting a discharge port (not shown) of the compressor 330 and the flow path switching mechanism 332. The first gas-side pipe 353 is a pipe connecting the flow path switching mechanism 332 and the gas side of the heat source-side heat exchanger 340. The liquid-side pipe 354 is a pipe connecting the liquid side of the heat source-side heat exchanger 340 and the liquid-side shutoff valve 302. The second expansion mechanism 344 is disposed in the liquid-side pipe 354. The second gas-side pipe 355 is a pipe connecting the flow path switching mechanism 332 and the gas-side shutoff valve 304.

(2-1-2) compressor

The compressor 330 sucks a low-pressure refrigerant in the refrigeration cycle through a suction pipe 351, compresses the refrigerant by a compression mechanism (not shown), and discharges a high-pressure refrigerant in the compressed refrigeration cycle through a discharge pipe 352.

The compressor 330 is, for example, a scroll compressor. However, the type of the compressor 330 is not limited to a scroll type, and the compressor 330 may be a screw type, a rotary type, or the like. The compressor 330 may be a variable-capacity compressor or a fixed-capacity compressor, for example.

(2-1-3) flow passage switching mechanism

The flow path switching mechanism 332 is a mechanism that switches the flow direction of the refrigerant in the refrigerant circuit 50 according to the operation mode of the heat load processing system 1. The operation modes of the heat load processing system 1 include a mode in which the liquid medium is cooled (hereinafter, referred to as a cooling mode) and a mode in which the liquid medium is heated (hereinafter, referred to as a heating mode).

In the present embodiment, the flow path switching mechanism 332 is a four-way selector valve. However, the fluid switching mechanism 332 is not limited to a four-way selector valve, and may be configured to be capable of switching the flow direction of the refrigerant as described below by combining a plurality of solenoid valves and pipes.

In the cooling mode, the flow path switching mechanism 332 switches the flow direction of the refrigerant in the refrigerant circuit 50 such that the refrigerant discharged from the compressor 330 is sent to the heat source side heat exchanger 340. Specifically, in the cooling mode, the flow path switching mechanism 332 causes the suction pipe 351 to communicate with the second gas side pipe 355 and causes the discharge pipe 352 to communicate with the first gas side pipe 353 (see the solid line in the flow path switching mechanism 332 in fig. 2).

In the heating mode, the flow path switching mechanism 332 switches the flow direction of the refrigerant in the refrigerant circuit 50 such that the refrigerant discharged from the compressor 330 is sent to the use side heat exchanger 10 of the heat exchange unit 100. Specifically, in the heating mode, the flow path switching mechanism 332 causes the suction pipe 351 to communicate with the first gas-side pipe 353 and causes the discharge pipe 352 to communicate with the second gas-side pipe 355 (see the broken line in the flow path switching mechanism 332 in fig. 2).

(2-1-4) Heat Source side Heat exchanger

The heat source-side heat exchanger 340 is a heat exchanger that exchanges heat between air around the heat source unit 300 and the refrigerant flowing through the inside of the heat source-side heat exchanger 340. The type of the heat source-side heat exchanger 340 is not limited, and is, for example, a cross-fin-and-tube type heat exchanger. When the operation mode of the heat load processing system 1 is the cooling mode, the heat source-side heat exchanger 340 functions as a condenser (radiator). Further, when the operation mode of the heat load handling system 1 is in the heating mode, the heat source side heat exchanger 340 functions as an evaporator.

(2-1-5) second expansion mechanism

The second expansion mechanism 344 is a mechanism that expands the refrigerant flowing through the liquid-side pipe 354 to adjust the pressure and flow rate of the refrigerant. In the present embodiment, the second expansion mechanism 344 is an electronic expansion valve whose opening degree can be adjusted. The second expansion mechanism 344 is not limited to an electronic expansion valve. The second expansion mechanism 344 may be an automatic temperature expansion valve having a temperature sensing cylinder, or may be a capillary tube.

(2-1-6) Fan

The fan 342 is a mechanism that generates an air flow so as to cause air to flow through the heat-source-side heat exchanger 340 in order to promote heat exchange between the refrigerant and the air in the heat-source-side heat exchanger 340. The type of the fan 342 is not limited, and is, for example, a propeller fan.

(2-1-7) liquid side stop valve

The liquid-side shutoff valve 302 is a valve that switches communication/non-communication between the liquid refrigerant communication tube 52 and the liquid-side pipe 354. The liquid refrigerant communication tube 52 is connected to one end of the liquid-side shutoff valve 302, and the liquid-side pipe 354 (see fig. 2) is connected to the other end of the liquid-side shutoff valve 302.

(2-1-8) gas side stop valve

The gas-side shutoff valve 304 is a valve that switches between communication and non-communication between the gas refrigerant communication tube 54 and the second gas-side pipe 355. The refrigerant communication tube 54 is connected to one end of the gas-side shutoff valve 304, and the second gas pipe 355 is connected to the other end of the gas-side shutoff valve 304 (see fig. 2).

(2-1-9) Heat Source side control substrate

The heat source-side control board 395 functions as a controller 95a together with a heat exchanger unit-side control board 95 of the heat exchanger unit 100 described later. The control section 95a will be described later.

The heat source side control substrate 395 includes various circuits, a microcomputer including a CPU and a memory storing a program to be executed by the CPU, and the like.

(2-2) refrigerant connection pipe

(2-2-1) liquid refrigerant connection pipe

The liquid refrigerant communication tube 52 connects the liquid-side shutoff valve 302 of the heat source unit 300 and the liquid-side connection port 100a of the heat exchanger unit 100, and connects the liquid-side pipe 354 of the heat source unit 300 and the heat exchanger unit internal liquid-side pipe 56 of the heat exchanger unit 100. For example, the connection of the liquid refrigerant communication tube 52 and the liquid-side connection port 100a of the heat exchanger unit 100 is performed by a flare joint. However, the method of connecting the liquid refrigerant communication tube 52 to the liquid-side connection port 100a of the heat exchanger unit 100 is not limited to the connection method using the flare joint, and for example, a connection method using a flange joint or a brazing connection may be selected.

(2-2-2) gas refrigerant connection pipe

The gas refrigerant communication tube 54 connects the gas-side shutoff valve 304 of the heat source unit 300 and the gas-side connection port 100b of the heat exchanger unit 100, and connects the second gas-side pipe 355 of the heat source unit 300 and the heat exchanger unit interior gas-side pipe 58 of the heat exchanger unit 100. The gas refrigerant communication tube 54 is, for example, brazed to the gas-side connection port 100b of the heat exchanger unit 100. However, the method of connecting the gas refrigerant communication tube 54 to the gas-side connection port 100b of the heat exchanger unit 100 is not limited to the brazing connection, and various pipe joints may be used.

(2-3) liquid Medium Circuit

The liquid medium circuit 400 is a circuit for circulating a liquid medium. The liquid medium circuit 400 is configured such that the use-side heat exchanger 10 and the use-side equipment 410 of the heat exchange unit 100 are connected to each other via a pipe.

The liquid medium circuit 400 includes the use-side heat exchanger 10 and the pump 60 of the heat exchanger unit 100, the use-side equipment 410, the heat exchanger unit internal first liquid medium pipe 66, the heat exchanger unit internal second liquid medium pipe 68, the heat exchanger unit internal communication pipe 67, the first communication pipe 422, and the second communication pipe 424.

The use side heat exchanger 10 and the pump 60 of the heat exchanger unit 100 will be described later.

As described above, the utilization-side device 410 is, for example, an air handling unit or a fan coil unit. As described above, the use-side device 410 may be a manufacturing device that cools and heats a manufacturing apparatus or a product using the liquid medium cooled and heated in the heat exchanger unit 100, or may be a container that stores the liquid medium cooled and heated in the heat exchanger unit 100.

The heat exchanger unit internal first liquid medium pipe 66 is a pipe connecting the liquid medium inlet 62 of the heat exchanger unit 100 and the use side heat exchanger 10 (particularly, the first heat exchanger 10a described later). The pump 60 is disposed in the first liquid medium pipe 66 in the heat exchanger unit.

The second liquid medium pipe 68 in the heat exchanger unit is a pipe that connects the use side heat exchanger 10 (particularly, the second heat exchanger 10b described later) and the liquid medium outlet 64 of the heat exchanger unit 100.

The heat exchanger unit internal communication pipe 67 is a pipe for connecting the first heat exchanger 10a and the second heat exchanger 10b described later.

The first communication pipe 422 is a pipe for connecting the use-side equipment 410 and the liquid medium inlet 62 of the heat exchanger unit 100. The connection method is not limited, and the first connection pipe 422 is connected to the liquid medium inlet 62 of the heat exchanger unit 100 by, for example, a flange joint. The first communication pipe 422 may be screwed or welded to the liquid medium inlet 62 of the heat exchanger unit 100.

The second communication pipe 424 is a pipe for connecting the liquid medium outlet 64 of the heat exchanger unit 100 and the use-side device 410. The connection method is not limited, and the second communication pipe 424 is connected to the liquid medium outlet 64 of the heat exchanger unit 100 by, for example, a flange joint. The second communication pipe 424 may be screwed or welded to the liquid medium outlet 64 of the heat exchanger unit 100.

When the pump 60 is operated, the liquid medium flows in the liquid medium circuit 400 in the following manner.

The liquid medium flowing out of the utilization-side device 410 flows in the first communication pipe 422 toward the liquid medium inlet 62 of the heat exchange unit 100. The liquid medium flowing into the heat exchanger unit 100 from the liquid medium inlet 62 flows into the use side heat exchanger 10 through the heat exchanger unit internal first liquid medium pipe 66. The liquid medium is cooled and heated by heat exchange with the refrigerant flowing through the refrigerant circuit 50 when passing through the use side heat exchanger 10. The liquid medium cooled/heated in the use side heat exchanger 10 flows out of the use side heat exchanger 10, and flows through the second liquid medium pipe 68 in the heat exchanger unit toward the liquid medium outlet 64. The liquid medium flowing from the liquid medium outlet 64 to the outside of the heat exchanger unit 100 flows through the second communication pipe 424 and flows into the use-side device 410.

(2-4) Heat exchanger Unit

The heat exchange unit 100 is a unit that performs at least one of cooling and heating of the liquid medium by exchanging heat between the liquid medium sent to the usage-side device 410 and the refrigerant. As described above, the heat exchanger unit 100 according to the present embodiment performs both cooling and heating of the liquid medium by exchanging heat between the liquid medium sent to the use-side device 410 and the refrigerant.

In the case where the heat exchanger unit 100 is a unit for the purpose of cooling only the liquid medium, the heat source unit 300 may not include the flow path switching mechanism 332. In addition, when the heat exchanger unit 100 is a unit that is intended only to heat the liquid medium, the heat source unit 300 may not include the flow path switching mechanism 332, particularly, when a reverse cycle defrosting operation in which the refrigerant discharged from the compressor 330 is supplied to the heat source-side heat exchanger 340 to remove frost adhering to the heat source-side heat exchanger 340 is not performed.

The heat exchange unit 100 mainly includes a casing 90, a water collection tray 80, a use side heat exchanger 10, a first expansion mechanism 20, a pump 60, a gas detection sensor 70, and an electrical component box 92 (see fig. 4 to 7).

The heat exchanger unit 100 has the same number of first expansion mechanisms 20 as the number of heat source units 300 (as the number of refrigerant circuits 50 formed by the heat source units 300 and the heat exchanger unit 100). In the present embodiment, the heat exchanger unit 100 includes four first expansion mechanisms 20.

The heat exchange unit 100 of the present embodiment includes two use side heat exchangers 10 (a first heat exchanger 10a and a second heat exchanger 10b) connected in series in the liquid medium circuit 400. However, the number of use side heat exchangers 10 is an example, and is not limited to two. For example, the heat exchanger unit 100 may have the same number of (four here) use-side heat exchangers 10 as the heat source units 300 connected in series in the liquid medium circuit 400. For example, the heat exchanger unit 100 may have only one use side heat exchanger 10, and the use side heat exchangers 10 may be connected to all (here, four) heat source units 300 to form the same number of refrigerant circuits 50 as the number of the heat source units 300. The heat exchanger unit 100 may have a plurality of use side heat exchangers 10 connected in parallel in the liquid medium circuit 400.

The heat exchanger unit 100 of the present embodiment includes one pump 60. However, the heat exchanger unit 100 may have a plurality of pumps 60 connected in series or in parallel in the liquid medium circuit 400.

(2-4-1) outer case

The casing 90 houses various components and various devices of the heat exchange unit 100 including the water collection tray 80, the use side heat exchanger 10, the first expansion mechanism 20, the pump 60, the gas detection sensor 70, and the electrical component box 92. The top and side surfaces of the heat exchanger block 100 are enclosed by top and side plates (refer to fig. 1).

A water collection tray 80 (see fig. 6) is disposed at a lower portion in the casing 90. The use side heat exchanger 10 and the pump 60 are disposed above the water collection tray 80 (see fig. 6). The first expansion mechanism 20 is disposed in front of the use side heat exchanger 10 and near the upper end of the use side heat exchanger 10 (see fig. 6). The electrical component box 92 is disposed on the upper front side of the housing 90 (see fig. 7). The electrical component box 92 is disposed above the use-side heat exchanger 10 and the pump 60 (see fig. 6).

The front surface of the housing 90 is provided with an opening 91a for maintenance (see fig. 6). The rear surface of the housing 90 is provided with an opening 91b for maintenance (see fig. 9). Normally, when the heat load processing system 1 is in operation, the openings 91b and 91b of the casing 90 are closed by the side plates of the casing 90. By removing the side plates of the casing 90 provided in the openings 91a and 91b, maintenance and replacement of parts and equipment inside the casing 90 can be performed.

A liquid-side connection port 100a and a gas-side connection port 100b of the heat exchanger unit 100 are provided at four locations on the front surface of the casing 90 (the lower right portion of the casing 90 in fig. 4). The liquid refrigerant communication tube 52 is connected to each liquid-side connection port 100a (see fig. 2). The gas refrigerant communication tube 54 (see fig. 2) is connected to each gas-side connection port 100 b. A liquid medium inlet 62 and a liquid medium outlet 64 of the heat exchanger unit 100 are provided on the rear surface of the casing 90 (see fig. 5 and 7). The liquid medium inlet 62 is connected to a first communication pipe 422 (see fig. 2). The liquid medium outlet 64 is connected to a second communication pipe 424 (see fig. 2).

The positions of the liquid-side connection port 100a, the gas-side connection port 100b, the liquid medium inlet 62, and the liquid medium outlet 64 are not limited to the positions shown in the drawings, and may be changed as appropriate.

(2-4-2) Water collecting tray

Referring to fig. 5 to 10, the water collection tray 80 will be described.

Fig. 8 is a schematic plan view of the water collection tray 80. Fig. 9 is a schematic rear view of a portion of the housing 90 (near the water collection tray 80) and the water collection tray of fig. 8. Fig. 10 is a schematic right side view of the water collection tray 80.

The water collection tray 80 is disposed at a lower portion of the housing 90. In particular, in the present embodiment, the water collection tray 80 is disposed at the lowermost portion of the casing 90. The water collection tray 80 is disposed below the use side heat exchanger 10. The water collection tray 80 is disposed below the pump 60. The water collection tray 80 receives the condensed water generated in the use side heat exchanger 10, the pump 60, the piping through which the liquid medium and the refrigerant flow, and the like. In addition, when the heat exchanger unit 100 is installed outdoors, rainwater and the like also flow into the water collection tray 80. In addition, the water collection tray 80 may also have a function as a bottom plate of the housing 90.

The water collection tray 80 is preferably disposed below at least a part of the refrigerant piping 57, the first liquid medium piping 66 in the heat exchanger unit, at least a part of the heat exchanger unit communication piping 67 and the heat exchanger unit second liquid medium piping 68, the use side heat exchanger 10, and the pump 60, which will be described later. Preferably, the water collection tray 80 is configured to enclose a majority of the lower portion of the heat exchanger package 100. For example, the water collection tray 80 covers 80% or more of the area of the heat exchanger unit 100 (the bottom area of the casing 90) in a plan view.

The water collection tray 80 has a floor 82 and side walls 84. The bottom plate 82 has a substantially rectangular shape in plan view (see fig. 8 to 10). The side wall 84 extends upward from the outer peripheral edge of the bottom plate 82 (see fig. 9 and 10). Although not limited, the height from the bottom plate 82 to the upper end 84a of the side wall 84 is about 80mm at the highest portion. That is, the height from the outer peripheral edge of the bottom plate 82 on the rear side to the upper end 84a of the side wall 84 is about 80 mm.

Here, a space formed above the bottom plate 82 of the water collection tray 80 and below the upper end portion 84a of the side wall 84 of the water collection tray 80 is referred to as an internal space of the water collection tray 80. The inner space Si of the water collection tray 80 is a space which is surrounded by the bottom plate 82 and the side wall 84 at the lower side and the side and is opened at the upper side. In other words, the internal space Si of the water collection tray 80 is a space surrounded by the bottom plate 82, the side wall 84, and an imaginary plane passing through the upper end 84a of the side wall 84. The condensed water dropping into the internal space Si of the water collection tray 80 is temporarily received in the internal space Si and discharged from the drain port provided in the water collection tray 80. The drain opening is an opening for discharging water in the internal space Si of the water collection tray 80. The drain opening is provided in at least one of the bottom plate 82 and the side wall 84 of the water collection tray 80. In the present embodiment, a drain pipe 86 is attached to the side wall 84 disposed on the rear side of the water collection tray 80 so as to communicate with the internal space Si of the water collection tray 80, and an end portion of the drain pipe 86 on the internal space Si side functions as a drain port 86a (see fig. 8). The drain port 86a is provided in the center of the side wall 84 disposed on the rear side of the water collection tray 80. In other words, the drain pipe 86 is attached to the center of the side wall 84 disposed on the rear side of the water collection tray 80. The drain pipe 86 is attached to a lower portion of the side wall 84 disposed on the rear side of the water collection tray 80 (see fig. 9).

In the present embodiment, the drain port is provided only at one location of the water collection tray 80, but the present invention is not limited thereto, and the drain port may be provided at a plurality of locations. The drain port is not necessarily formed of a pipe fixed to the bottom plate 82 or the side wall 84 of the water collection tray 80, and a hole may be formed only in the bottom plate 82 or the side wall 84 of the water collection tray 80 as the drain port.

The bottom plate 82 of the water collection tray 80 has an inclined portion 82a inclined with respect to a horizontal plane. In particular, in the present embodiment, the entire bottom plate 82 is inclined with respect to the horizontal plane, and the entire bottom plate 82 functions as the inclined portion 82 a. In the present embodiment, the inclined portion 82a is inclined so as to become lower from the front side to the rear side, and has an upper end 82aa on the front side and a lower end 82ab on the rear side (see fig. 10). That is, in the present embodiment, the bottom plate 82 is lowered toward the side wall 84 disposed on the rear side of the water collection tray 80 where the drain port 86a is provided, so that water is easily drained from the internal space Si of the water collection tray 80 through the drain port 86 a.

The bottom plate 82 of the water collection tray 80 may not be entirely inclined with respect to the horizontal plane as in the present embodiment. That is, only a part of the bottom plate 82 may have the inclined portion 82 a. For example, the region of the bottom plate 82 of the water collection tray 80 where the possibility of the condensed water dropping is small may not be provided with the inclination.

(2-4-3) utilization side Heat exchanger

The use side heat exchanger 10 includes a first heat exchanger 10a and a second heat exchanger 10 b.

In the following description, the features common to the first heat exchanger 10a and the second heat exchanger 10b will be described as the use-side heat exchanger 10 without being distinguished from the first heat exchanger 10a or the second heat exchanger 10 b.

In the use side heat exchanger 10, heat exchange is performed between the refrigerant and the liquid medium. In the present embodiment, the use side heat exchanger 10 is a plate heat exchanger. However, the type of the use side heat exchanger 10 is not limited to a plate heat exchanger, and any type of heat exchanger that can be used for a refrigerant and a liquid medium may be appropriately selected.

The first heat exchanger 10a and the second heat exchanger 10b are connected to two heat exchanger unit internal liquid side pipes 56 and two heat exchanger unit internal gas side pipes 58, respectively. Further, the first heat exchanger 10a is connected to a heat exchanger block internal first liquid medium pipe 66 and a heat exchanger block internal communication pipe 67. The second heat exchanger 10b is connected to a heat exchanger unit internal communication pipe 67 and a heat exchanger unit internal second liquid medium pipe 68. The heat exchanger unit internal communication pipe 67 is a pipe that communicates the liquid medium flow path (not shown) in the first heat exchanger 10a with the liquid medium flow path in the second heat exchanger 10 b.

When the pump 60 is operated, the liquid medium flows into the first heat exchanger 10a through the first communication pipe 422 and the heat exchanger block first liquid medium pipe 66, and flows out to the heat exchanger block communication pipe 67 through a liquid medium passage (not shown) in the first heat exchanger 10 a. The liquid medium flowing out of the first heat exchanger 10a to the heat exchanger unit internal communication pipe 67 flows into the second heat exchanger 10b through the heat exchanger unit internal communication pipe 67. The liquid medium flowing into the second heat exchanger 10b passes through a liquid medium flow path (not shown) in the second heat exchanger 10b, and is further sent to the use-side equipment 410 through the second liquid medium pipe 68 and the second communication pipe 424 in the heat exchanger unit.

When the operation mode of the heat load handling system 1 is the cooling mode, the refrigerant flows into the refrigerant flow paths (not shown) in the respective use side heat exchangers 10 from the heat exchanger unit liquid side piping 56 in the respective use side heat exchangers 10. The liquid medium flowing through the liquid medium flow path (not shown) in each use side heat exchanger 10 is cooled by heat exchange with the refrigerant flowing through the refrigerant flow path (not shown) in each use side heat exchanger 10. The refrigerant flowing through the refrigerant flow path (not shown) in each use side heat exchanger 10 flows into the heat exchanger block interior gas side pipe 58, passes through the gas refrigerant communication tube 54, and flows into the second gas side pipe 355 of the heat source unit 300.

On the other hand, when the operation mode of the heat load handling system 1 is in the heating mode, the refrigerant flows into the refrigerant flow paths (not shown) in the respective use side heat exchangers 10 from the gas-side pipes 58 in the heat exchanger bank in the respective use side heat exchangers 10. The liquid medium flowing through the liquid medium flow path (not shown) in each use side heat exchanger 10 exchanges heat with the refrigerant flowing through the refrigerant flow path (not shown) in each use side heat exchanger 10. The refrigerant flowing through the refrigerant flow path (not shown) in each use side heat exchanger 10 flows into the heat exchanger unit interior liquid side pipe 56, passes through the liquid refrigerant communication tube 52, and flows into the liquid side pipe 354 of the heat source unit 300.

(2-4-4) first expansion mechanism

The first expansion mechanism 20 is a mechanism that expands the refrigerant flowing through the liquid-side pipe 56 in the heat exchanger unit to adjust the pressure and flow rate of the refrigerant.

In the present embodiment, the first expansion mechanism 20 is an electronic expansion valve whose opening degree can be adjusted. The electronic expansion valve as the first expansion mechanism 20 is disposed in front of the use side heat exchanger 10 and near the upper end of the use side heat exchanger 10. The first expansion mechanism 20 is not limited to an electronic expansion valve. The first expansion mechanism 20 may be an automatic temperature expansion valve having a temperature sensing cylinder, or may be a capillary tube.

(2-4-5) Pump

The pump 60 is a pump that feeds the liquid medium to the use-side device 410. The pump 60 is disposed in the heat exchanger unit in the first liquid medium pipe 66.

The pump 60 is, for example, a fixed speed vortex pump. However, the pump 60 is not limited to a vortex pump, and the type of the pump 60 may be appropriately selected. Further, the pump 60 may be a variable flow pump.

In the present embodiment, the pump 60 is disposed upstream of the use-side heat exchanger 10 in the flow direction of the liquid medium in the liquid medium circuit 400, in other words, disposed in the heat exchanger unit first liquid medium pipe 66. However, the pump 60 is not limited to this, and may be disposed downstream of the use side heat exchanger 10 in the flow direction of the liquid medium in the liquid medium circuit 400, in other words, disposed in the heat exchanger block second liquid medium pipe 68.

(2-4-6) gas detecting sensor

Gas detection sensor 70 is a sensor for detecting whether or not gas of the refrigerant is present in inner space Si of water collection tray 80. Preferably, the gas detection sensor 70 has a detection element 72, and detects whether or not the refrigerant gas is present at the location where the detection element 72 is disposed.

The detection element 72 is a semiconductor sensor element, for example. The conductivity of the semiconductor type detection element changes depending on the state of the gas without the refrigerant in the surroundings and the state of the gas with the refrigerant in the surroundings. The gas detection sensor 70 includes a detection circuit (not shown) electrically connected to the detection element 72, and detects the presence or absence of the refrigerant gas by detecting a change in the electrical conductivity of the detection element 72 by the detection circuit.

However, the detection element 72 is not limited to a semiconductor type element, and may be any element as long as it can detect the refrigerant gas. For example, the gas detection sensor 70 may include an infrared light source and an infrared detection element, not shown, as the detection element 72, and detect whether or not refrigerant gas is present by detecting a change in the amount of infrared detection of the detection element 72, which changes depending on whether or not refrigerant gas is present, by a detection circuit electrically connected to the detection element 72.

As described above, since the density of the refrigerant gas is higher than that of air, when the refrigerant leaks in the heat exchange unit 100, the refrigerant gas tends to move to a lower position. Therefore, the leaked refrigerant gas is likely to accumulate in the internal space Si of the water collection tray 80. In particular, in the present embodiment, the water collection tray 80 covers a large part of the lower side of the heat exchange unit 100, for example, 80% or more of the bottom area of the casing 90 in plan view, and therefore, leaked refrigerant gas is likely to accumulate in the internal space Si of the water collection tray 80. Therefore, the detection element 72 of the gas detection sensor 70 is preferably disposed in the internal space Si of the water collection tray 80 located at the lower portion in the housing 90. More preferably, the detection element 72 is disposed on the lower end 82ab side of the inclined portion 82a of the bottom plate 82 of the water collection tray 80 (the rear end side of the bottom plate 82 in the present embodiment). More preferably, the detection element 72 is disposed near the drain port 86a, and the drain port 86a is a drain port through which water is drained from the internal space Si of the water collection tray 80.

In the present embodiment, the detection element 72 of the gas detection sensor 70 is disposed in the internal space Si of the water collection tray 80 and on the lower end 82ab side of the inclined portion 82a (see fig. 10). The detection element 72 of the gas detection sensor 70 is disposed at a position adjacent to the drain port 86a provided in the side wall 84 on the rear side of the water collection tray 80 (see fig. 8 to 10). Since the detection element 72 is disposed at a position where the refrigerant gas is likely to accumulate as described above, refrigerant leakage detection with high reliability can be performed.

The position where the detection element 72 of the gas detection sensor 70 is disposed is an example, and is not limited to the position shown in fig. 8 to 10.

For example, the detection element 72 of the gas detection sensor 70 may be disposed at a position near the side wall 84 on the rear side of the water collection tray 80 (on the lower portion 82ab side of the inclined portion 82a), i.e., a position away from the drain port 86 a.

For example, when a location with a relatively high possibility of refrigerant gas leakage is determined, the detection element 72 of the gas detection sensor 70 may be disposed in the vicinity of the location with a relatively high possibility of refrigerant gas leakage in the internal space Si of the water collection tray 80. In this case, the detection element 72 of the gas detection sensor 70 may be disposed at a position other than the lower end 82ab side of the inclined portion 82a (for example, the upper end 82aa side of the inclined portion 82 a).

Further, for example, the detection element 72 of the gas detection sensor 70 may not be provided with the inner space Si of the water collection tray 80. For example, the gas detection sensor 70 may detect whether or not the gas of the refrigerant is present in the internal space Si of the water collection tray 80 by the detection element 72 disposed at a position higher than the upper end portion 84a of the side wall 84 of the water collection tray 80 and very close to the upper end portion 84 a. Gas detection sensor 70 may detect whether or not gas of the refrigerant is present in internal space Si of water collection tray 80 by detection element 72 disposed at a different location outside internal space Si of water collection tray 80 and capable of detecting gas in internal space Si of water collection tray 80. For example, the place outside the internal space Si of the water collection tray 80 where the gas in the internal space Si of the water collection tray 80 can be detected includes an opening portion of the drain pipe 86 on the opposite side of the drain port 86 a.

The detection element 72 of the gas detection sensor 70 is preferably disposed below an electric element that may be an ignition source (see fig. 6 and 7). By disposing the detection element 72 below the electrical component that may become an ignition source, even when a refrigerant leaks in the heat exchange unit 100, the leakage of the refrigerant is easily detected before the refrigerant gas reaches the height position of the electrical component that may become an ignition source from the bottom side of the casing 90.

In addition, the electrical components that may become ignition sources include electrical components that may generate electric sparks. In the present embodiment, the electrical components that may be an ignition source include electrical components 93 such as an electromagnetic switch, a contactor, and a relay housed in an electrical component box 92 described later, an electronic expansion valve as an example of the first expansion mechanism 20, and a terminal box 61 of the pump 60. An electric wire 61a for supplying electric power to the motor 60a of the pump 60 is connected to the terminal box 61 of the pump 60.

Although not installed in the heat exchanger unit 100 of the present embodiment, in a case where the heat exchanger unit 100 is installed in a cold district, a heater may be disposed in the heat exchanger unit 100. The heater may reach a high temperature to an extent sufficient to constitute an ignition source according to its specification. The electric components that may reach a high temperature to such an extent as to constitute an ignition source are also preferably disposed above the detection element 72 of the gas detection sensor 70.

Further, the detection element 72 of the gas detection sensor 70 is preferably disposed below the liquid-side connection port 100a and the gas-side connection port 100b of the heat exchange unit 100, which have a high possibility of becoming a leakage site of the refrigerant (see fig. 6 and 7). On the other hand, the electrical components that may be an ignition source are preferably disposed above the liquid-side connection port 100a and the gas-side connection port 100b of the heat exchanger unit 100. With the above arrangement, even when refrigerant leakage occurs at the liquid-side connection port 100a or the gas-side connection port 100b of the heat exchange unit 100, the refrigerant leakage can be easily detected before the refrigerant gas reaches a height position of an electrical component that may become an ignition source from the bottom side of the housing 90.

Further, it is preferable that the electric components that can be an ignition source (in the present embodiment, the electric components 93 such as the electromagnetic switch, the contactor, and the relay housed in the electric component box 92, the electronic expansion valve as an example of the first expansion mechanism 20, and the terminal box 61 of the pump 60) are disposed at a height position of 300mm or more from the bottom of the housing 90 (see fig. 6 and 7). By disposing the electrical components that may become ignition sources at the height positions, even when the refrigerant leaks, the possibility that the electrical components inside the casing 90 become ignition sources and cause ignition can be reduced.

In the case of a refrigerant leak, since there is a high possibility that the refrigerant leaks from the use side heat exchanger 10 or the refrigerant pipe 57 including the liquid side pipe 56 in the heat exchanger unit and the gas side pipe 58 in the heat exchanger unit, the detection element 72 of the gas detection sensor 70 is preferably disposed at a position described below.

The interior of the casing 90 is divided into at least a pump disposition region a1 in which the pump 60 is disposed and a refrigerant-side region a2 (see fig. 5 and 8) in which the refrigerant pipe 57 through which the refrigerant flows or the use-side heat exchanger 10 is disposed, as viewed in plan view. That is, in a plan view, the pump disposition region a1 and the refrigerant side region a2 are present inside the casing 90. As shown in fig. 8, the detection element 72 of the gas detection sensor 70 is preferably disposed in the vicinity of the refrigerant-side region a2 away from the pump disposition region a 1.

From the viewpoint of maintenance, the detection element 72 of the gas detection sensor 70 is preferably disposed in a space near the opening 91b for maintenance of the housing 90. The space near opening 91b is a space that can be reached by the operator through opening 91 b. For example, the space in the vicinity of the opening 91b is a space in a range touched by a hand from the opening 91b (for example, a space within 50cm from the opening 91 b). When the detection element 72 of the gas detection sensor 70 is disposed at the above position, the detection element 72 can be easily replaced and repaired by removing the side plate of the housing 90 that closes the opening 91 b.

Further, since the detection element 72 of the gas detection sensor 70 detects the refrigerant gas, it is preferable that the detection element 72 is disposed at a position where the detection element 72 is unlikely to be immersed in water even if condensed water accumulates in the internal space Si of the water collection tray 80.

For example, it is preferable that the heat exchanger unit 100 has a float 88, the float 88 is disposed in the inner space Si of the water collection tray 80, and the detection element 72 is attached to the upper surface 88a or the side surface 88b of the float 88. The float 88 is a member configured to float up to the water surface when condensed water accumulates in the internal space Si of the water collection tray 80.

More specifically, the structure of the float 88 will be described. For example, specifically, the float 88 has a body portion 881 and a swing shaft 882, and the swing shaft 882 is swingably supported by a support portion (not shown) provided on the side wall 84 of the water collection tray 80 or a frame (not shown) of the housing 90 (see fig. 11A and 11B). The body portion 881 is configured to float in water. The detection element 72 of the gas detection sensor 70 may be attached to the upper surface 88a (upper surface of the body portion 881) of the float 88 as shown in fig. 11A, or may be attached to the side surface 88B (side surface of the body portion 881) of the float 88 as shown in fig. 11B. When there is no water in the water collection tray 80, the body portion 881 of the float 88 is in the first position. Although not limited, the main body portion 881 of the float 88 in the first position contacts the bottom plate 82 of the water collection tray 80 as shown by the solid lines in fig. 11A and 11B. On the other hand, when water accumulates in the water collection tray 80, the main body portion 881 of the float 88 swings about the swing shaft 882, floating upward by buoyancy as shown by the two-dot chain line in fig. 11A and 11B. With the above configuration, even when condensed water accumulates in the internal space Si of the water collection tray 80, the detection element 72 of the gas detection sensor 70 is easily prevented from being immersed in water. Therefore, for example, even when the water discharge pipe 86 is clogged due to some cause and water cannot be discharged from the water discharge port 86a, the gas detection sensor 70 can detect the gas refrigerant when the refrigerant leaks.

In addition, the heat exchange unit 100 may not have the float 88. The detection element 72 of the gas detection sensor 70 may be directly attached to the side wall 84 of the water collection tray 80 or a frame (not shown) of the housing 90. In this case, the detection element 72 of the gas detection sensor 70 is preferably disposed at a position where it is not easily soaked in water, for example, at a position higher than the drain port 86a in the internal space Si of the water collection tray 80 shown by a reference numeral 72a in fig. 9.

(2-4-7) Electrical component Box

The electrical component box 92 is a housing that houses various electrical components. The electrical component box 92 houses electrical components 93 (see fig. 2) such as a heat exchanger unit side control board 95, a power supply terminal block (not shown), an electromagnetic switch, a contactor, and a relay. The electric component 93 may not include all of the electromagnetic switch, the contactor, and the relay, or may include only one of the electromagnetic switch, the contactor, and the relay. The electric components housed in the electric component box 92 are not limited to the illustrated example, and various electric components may be housed as necessary.

The heat exchanger unit-side control board 95 functions as a controller 95a together with the heat source-side control board 395 of the heat source unit 300. The heat exchanger unit-side control board 95 includes various circuits, a microcomputer including a CPU and a memory, and the like, and the memory stores a program to be executed by the CPU.

The controller 95a controls the operations of the respective units of the heat load processing system 1.

The controller 95a is electrically connected to various devices of the heat source unit 300 and the heat exchanger unit 100. The various devices of the heat source unit 300 and the heat exchanger unit 100 connected to the controller 95a include the compressor 330, the flow path switching mechanism 332, the second expansion mechanism 344, and the fan 342 of the heat source unit 300, and the first expansion mechanism 20 and the pump 60 of the heat exchanger unit 100. The control unit 95a is communicably connected to various sensors included in the heat source unit 300 and the heat exchanger unit 100, and receives measurement values from various sensors (not shown). The various sensors that the heat exchange unit 100 has are not limited, and include, for example: temperature sensors disposed in the heat exchanger unit liquid side pipe 56 and the heat exchanger unit gas side pipe 58 for measuring the temperature of the refrigerant; a pressure sensor provided in the liquid-side pipe 56 in the heat exchanger unit; and temperature sensors for measuring the temperature of the liquid medium, which are provided in the heat exchanger unit first liquid medium pipe 66, the heat exchanger unit internal communication pipe 67, and the heat exchanger unit internal second liquid medium pipe 68. The various sensors included in the heat source unit 300 are not limited, and include, for example, a temperature sensor provided in the intake pipe 351 to measure the intake temperature, a temperature sensor provided in the discharge pipe 352 to measure the discharge temperature, and a pressure sensor to measure the discharge pressure. The control unit 95a is communicably connected to the gas detection sensor 70 of the heat source unit 300.

The control unit 95a controls the operation of various devices of the heat source unit 300 and the heat exchanger unit 100 in accordance with an operation/stop command provided from an operation device, not shown. The control unit 95a controls the state of the flow path switching mechanism 332 of the heat source unit 300 according to the operation mode (cooling mode/heating mode) of the heat load processing system 1. The controller 95a controls the operations of the various devices of the heat source unit 300 and the heat exchanger unit 100 such that the liquid refrigerant is cooled/heated to reach a predetermined target temperature, and flows out from the liquid medium outlet 64 of the heat exchanger unit 100. Since the operating principle of the vapor compression refrigerator is well known, the description thereof is omitted here. When the gas detection sensor 70 detects a leak of the refrigerant gas, the controller 95a controls the various devices to operate the various devices of the heat source unit 300 and the heat exchanger unit 100 at a predetermined leak time.

(3) Feature(s)

(3-1)

The heat exchange unit 100 according to the above-described embodiment performs at least one of cooling and heating of the liquid medium by exchanging heat between the liquid medium sent to the usage-side device 410 and the refrigerant. The heat exchange unit 100 includes a use side heat exchanger 10, which is an example of a heat exchanger, a casing 90, a water collection tray 80, and a gas detection sensor 70. The gas detection sensor 70 is an example of a first gas detection sensor. In the use side heat exchanger 10, heat is exchanged between the combustible refrigerant and the liquid medium. The casing 90 houses the use side heat exchanger 10. The water collection tray 80 is disposed below the use side heat exchanger 10 and below the casing 90. The water collection tray 80 has a bottom plate 82 and a side wall 84 extending upward from the bottom plate 82. Gas detection sensor 70 detects the presence of gas in the refrigerant in an internal space Si of water collection tray 80, which is located above bottom plate 82 of water collection tray 80 and below the upper end of side wall 84 of water collection tray 80.

Generally, the refrigerant gas is heavier than air, and when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in the present heat exchanger unit 100, the leaked refrigerant gas is likely to accumulate in the water collection tray 80 disposed at the lower portion of the casing 90 and receiving the dew condensation water and the like generated in the piping, the heat exchanger, and the like.

Here, by detecting whether or not the refrigerant gas is present in the internal space Si of the water collection tray 80 in which the leaked refrigerant gas easily accumulates, it is possible to detect the leakage of the refrigerant gas with high reliability.

Preferably, the gas detection sensor 70 has a detection element 72, which is an example of a first detection element, disposed in the internal space Si of the water collection tray 80, and detects whether or not the gas of the refrigerant is present at a location where the detection element 72 is disposed.

Here, by disposing the detection element 72 of the gas detection sensor 70 in the internal space Si of the water collection tray 80 in which leaked refrigerant easily accumulates, leakage detection of refrigerant gas with high reliability can be performed.

(3-2)

In the heat exchanger unit 100 of the above embodiment, the bottom plate 82 of the water collection tray 80 has the inclined portion 82a inclined with respect to the horizontal plane. The detection element 72 is disposed on the lower end side of the inclined portion 82 a.

Here, since the detection element of the gas detection sensor 70 is disposed on the lower end side of the inclined portion 82a where refrigerant gas is likely to collect, refrigerant leakage detection with high reliability can be performed.

(3-3)

In the heat exchanger unit 100 according to the above embodiment, the drain port 86a is provided in at least one of the bottom plate 82 and the side wall 84 of the water collection tray 80, and the drain port 86a is used to drain water in the internal space Si of the water collection tray 80. The detection element 72 is disposed near the drain opening 86 a.

Here, since the detection element 72 of the gas detection sensor 70 is disposed in a position where water is easily discharged, in other words, in the vicinity of the water discharge port 86a of the water collection tray 80 where water (fluid) easily flows out, refrigerant leakage detection with high reliability can be performed.

(3-4)

The heat exchanger unit 100 according to the above embodiment includes the float 88 disposed in the internal space Si of the water collection tray 80. The detection element 72 is mounted to the upper surface 88a or the side surface 88b of the float 88.

Here, since the detection element 72 of the gas detection sensor 70 is attached to the upper surface 88a or the side surface 88b of the float 88, the refrigerant leakage can be detected even in a state where water is accumulated in the water collection tray 80.

(3-5)

In the heat exchanger unit 100 of the above embodiment, the opening 91b for maintenance is formed in the housing 90. The detection element 72 is disposed in the space near the opening 91 b.

Here, since the detection element 72 of the gas detection sensor 70 is disposed in the space near the opening 91b for maintenance, the detection element 72 of the gas detection sensor 70 can be easily inspected and replaced.

(3-6)

The heat exchanger unit 100 of the above embodiment includes the pump 60. The pump 60 is disposed inside the casing 90. The pump 60 supplies the liquid medium to the utilization-side device 410. The interior of the casing 90 is divided into at least a pump disposition region a1 and a refrigerant-side region a2 in plan view. The pump disposition area a1 disposes the pump 60. The refrigerant-side region a2 has the refrigerant pipe 57 or the use-side heat exchanger 10 through which the refrigerant flows. In a plan view, the detection element 72 is disposed in the vicinity of the refrigerant-side region a2 apart from the pump disposition region a 1.

Here, since the detection element 72 of the gas detection sensor 70 is disposed in the casing 90 at a position relatively close to the refrigerant pipe 57 or the use side heat exchanger 10 through which the refrigerant flows, refrigerant leakage detection with high reliability can be performed.

(4) Modification example

(4-1) modification 1A

The heat exchanger unit 100 of the above embodiment includes the pump 60, but is not limited thereto. The pump 60 may be disposed outside the casing 90 separately from the heat exchanger assembly 100.

(4-2) modification 1B

The heat exchanger unit 100 may further include an auxiliary gas detection sensor 270, in addition to the gas detection sensor 70 in which the detection element 72 is disposed in the internal space Si of the water collection tray 80, and the auxiliary gas detection sensor 270 may include a detection element 272 (see fig. 12) disposed outside the casing 90.

The auxiliary gas detection sensor 270 is a sensor that detects whether or not the gas of the refrigerant is present at the location where the detection element 272 is disposed. The auxiliary gas detection sensor 270 is the same as the gas detection sensor 70 except for the installation place of the detection element 272.

Since the heat exchange unit 100 includes the auxiliary gas detection sensor 270, the refrigerant gas can be detected by the auxiliary gas detection sensor 270 even when the refrigerant gas flows out of the casing 90, and safety is high.

Further, as described above, since the density of the refrigerant gas is higher than the density of the air, the detection element 272 of the auxiliary gas detection sensor 270 is preferably disposed in the vicinity of the floor surface FL of the unit installation space (for example, the machine room R) in which the heat exchange unit 100 is installed. For example, the detection element 272 is preferably disposed at a position lower than a height position 300mm above the floor surface FL of the machine room R. For example, the heat exchanger unit 100 may be provided in the machine room R on a base (rack) 2 provided on the floor surface FL (see fig. 12). In the above case, the detection element 272 of the auxiliary gas detection sensor 270 is preferably disposed in the vicinity of the floor surface FL of the machine room R. The detection element 272 of the auxiliary gas detection sensor 270 is preferably disposed at a height position within 300mm above the floor surface FL of the machine room R. In this case, the detection element 272 of the auxiliary gas detection sensor 270 may be disposed at a position lower than the bottom of the casing 90 of the heat exchanger unit 100.

(4-3) modification 1C

In the above embodiment, the liquid medium cooled/heated by the heat exchanger unit 100 circulates in the liquid medium circuit 400, but the present invention is not limited thereto. For example, in the case of directly using the cooled/heated liquid medium itself, the liquid medium to be supplied to the use-side device 410 (e.g., a tank) may be directly used without circulating in the liquid medium circuit 400.

< second embodiment >

(1) Integral structure

A heat exchanger unit 200 and a heat load processing system 201 including the heat exchanger unit 100 of the second embodiment will be explained with reference to the drawings.

Fig. 13 is a perspective view of the heat exchanger unit 200. Fig. 14 is a schematic configuration diagram of a heat load processing system 201 including a heat exchanger unit 200. In addition, the heat exchanger package 200 has three systems for the same refrigerant circuit 150, only one of which, the refrigerant circuit 150, is depicted in fig. 14. Fig. 15 is a schematic plan view of a lower section of the inside of the casing 190 of the heat exchanger unit 200. Fig. 16 is a schematic front view of the heat exchanger unit 200 with a side plate of the housing 190 removed. Fig. 17 is a schematic right side view of the heat exchanger unit 200 with a side plate of the housing 190 removed. Fig. 18 is a schematic rear view of a portion of the housing 190 (near the water collection tray 80) and the water collection tray 80 of the heat exchanger package 200.

In the following description, expressions indicating directions such as "up", "down", "left", "right", "front (front)", "rear (back)" and the like are sometimes used. These directions represent the directions indicated by arrows in the drawings, unless otherwise specified.

First, the differences between the heat load processing system 201 and the heat load processing system 1 according to the first embodiment will be summarized.

In the heat load processing system 1, the heat source-side heat exchanger 340 cools and heats the refrigerant by exchanging heat between the refrigerant and the air around the heat source unit 300. In contrast, in the heat load processing system 201, the refrigerant is cooled/heated by heat exchange between the heat-source-side liquid medium flowing through the heat-source-side liquid medium circuit 500 and the refrigerant. In addition, in the present embodiment, the heat load processing system 201 is a system in which the refrigerant is cooled by the cooling water flowing in the heat source side liquid medium circuit 500, and the liquid medium sent to the utilization side equipment 410 is cooled by the refrigerant in the heat exchange unit 200. However, the heat load processing system 201 is not limited to this, and may be a system in which the refrigerant is heated by the heat-source-side liquid medium (for example, waste hot water) flowing through the heat-source-side liquid medium circuit 500, and the liquid medium sent to the usage-side equipment 410 is heated by the refrigerant in the heat exchanger unit 200. The heat load handling system 201 may be a system capable of switching between a cooling mode in which the refrigerant is cooled by the heat-source-side liquid medium having a relatively low temperature flowing through the heat-source-side liquid medium circuit 500 and the liquid medium sent to the usage-side device 410 is cooled by the refrigerant in the heat exchanger unit 200, and a heating mode in which the refrigerant is heated by the heat-source-side liquid medium having a relatively high temperature flowing through the heat-source-side liquid medium circuit 500 and the liquid medium sent to the usage-side device 410 is heated by the refrigerant in the heat exchanger unit 200. In the following description, the liquid medium flowing through the heat-source-side liquid medium circuit 500 is referred to as a heat-source-side liquid medium, and the liquid medium to be sent to the usage-side device 410 is simply referred to as a liquid medium.

In the thermal load handling system 1, the heat source unit 300 and the heat exchanger unit 100 form the refrigerant circuit 50. In contrast, in the thermal load handling system 201, the heat exchanger unit 200 has the entire refrigerant circuit 150. In the present embodiment, one heat exchanger unit 200 includes three refrigerant circuits 150. However, the heat exchanger package 200 may have one or two systems of refrigerant circuits 150, or more than four systems of refrigerant circuits 150.

Next, the overall configuration of the heat load processing system 201 will be described.

The heat load processing system 201 mainly includes a heat exchanger unit 200, a heat source-side liquid medium circuit 500, and a utilization-side device 410.

The heat exchanger unit 200 is a device that performs at least one of cooling and heating of the liquid medium by exchanging heat between the liquid medium sent to the usage-side equipment 410 and the refrigerant. The liquid medium cooled/heated by the liquid refrigerant in the heat exchanger unit 200 is sent to the utilization-side equipment 410.

The heat exchanger unit 200 illustrated and exemplified in fig. 14 is a unit that cools only a liquid medium by exchanging heat between the liquid medium and a refrigerant. However, the heat exchanger unit 200 is not limited to this, and may be a unit that performs only heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant. Further, the heat exchanger unit 200 may be a device capable of performing both cooling and heating of the liquid medium by exchanging heat between the liquid medium and the refrigerant, as in the heat exchanger unit 100 of the first embodiment.

The liquid medium and the refrigerant used in the present embodiment are the same as those described in the first embodiment. Here, the description is omitted. The heat source-side liquid medium used in the present embodiment is, for example, water or brine.

The heat-source-side liquid medium circuit 500 is a liquid medium circuit in which a heat-source-side liquid medium circulates, and the heat-source-side liquid medium cools the refrigerant in the heat exchange unit 200. The heat-source-side liquid medium circuit 500 mainly includes a heat source device 510 and a heat-source-side pump 520.

In the present embodiment, the heat source device 510 is a device that cools the heat-source-side liquid medium. For example, the heat source device 510 is a cooling tower. The cooling tower may be an open-type cooling tower that directly cools the heat source-side heat medium, or may be a closed-type cooling tower that indirectly cools the heat source-side heat medium. The type of the heat-source-side liquid medium may be determined as appropriate depending on the type of the cooling tower and the like. The installation place is not limited, and the heat source device 510 is installed on, for example, a roof or a space around a building.

The heat-source-side pump 520 is a pump that feeds the heat-source-side liquid medium cooled by the heat-source device 510 to the heat exchanger unit 200. The heat source side pump 520 is, for example, a constant speed vortex pump. However, the heat-source-side pump 520 is not limited to a vortex pump, and the type of the heat-source-side pump 520 may be appropriately selected. The heat-source-side pump 520 may be a variable-flow pump. The installation location is not limited, and the heat-source-side pump 520 is installed in the same machine room R as the heat exchanger unit 200, for example.

As for the utilization-side apparatus 410, it is the same as the utilization-side apparatus 410 in the heat load processing system 1 of the first embodiment. However, in the second embodiment, the usage-side device 410 is a device that uses a liquid medium cooled by a refrigerant. For example, although not limiting, the utilization side device 410 is an air handling unit or a fan coil unit used only for cooling. The use-side device 410 is not limited to a device that uses a liquid medium cooled by a refrigerant. When the heat load processing system 201 is configured such that the liquid medium is heated by the refrigerant in the heat exchanger unit 200, the usage-side device 410 may be a device that uses the liquid medium heated by the refrigerant.

In addition, only one utilization-side device 410 is illustrated in fig. 14. However, the heat load processing system 201 may include a plurality of utilization-side devices, as in the first embodiment. In addition, when the heat load processing system 201 includes a plurality of utilization-side devices, the types of the utilization-side devices may be completely the same, or the utilization-side devices may include a plurality of types of devices.

(2) Detailed structure

The heat exchanger block 200 will be described in detail.

The liquid medium circuit 400A of the second embodiment is the same as the liquid medium circuit 400 of the first embodiment except for the point that the pump 160 (the same device as the pump 60 of the first embodiment) is disposed outside the heat exchanger unit 200 (the first communication pipe 422) and the configuration of the liquid medium pipe in the heat exchanger unit 200. Here, in the description of the heat exchanger unit 200, the liquid medium piping in the heat exchanger unit 200 will be described, and the detailed description of the liquid medium circuit 400A other than this will be omitted.

(2-1) Heat exchanger Unit

The heat exchanger unit 200 will be described with reference to fig. 13 to 18.

The heat exchanger train 200 has three systems of refrigerant circuits 150. In fig. 14, the refrigerant circuit 150 of only one of the three systems is depicted. Since the other refrigerant circuit 150 is the same as the refrigerant circuit 150 described here, the description thereof is omitted here.

The installation location of the heat exchanger unit 200 is the same as that of the heat exchanger unit 100 according to the first embodiment, and therefore, the description thereof is omitted.

The heat exchange unit 200 mainly includes a compressor 130, a heat source side heat exchanger 140, an expansion mechanism 120, a use side heat exchanger 110, a casing 190, a water collection tray 80, a gas detection sensor 70, and an electric component box 192. The compressor 130, the heat source side heat exchanger 140, the expansion mechanism 120, and the use side heat exchanger 110 are connected by refrigerant pipes 151, thereby constituting a refrigerant circuit 150. The refrigerant pipe 151 includes a first refrigerant pipe 151a connecting the discharge side of the compressor 130 and the gas side of the heat source side heat exchanger 140. The refrigerant pipe 151 includes a second refrigerant pipe 151b connecting the liquid side of the heat source side heat exchanger 140 and the liquid side of the usage side heat exchanger 110. The expansion mechanism 120 is disposed in the second refrigerant pipe 151 b. The refrigerant pipe 151 includes a third refrigerant pipe 151c connecting the gas side of the use side heat exchanger 110 and the suction side of the compressor 130. In addition, an unillustrated accumulator may be disposed in the third refrigerant pipe 151 c.

In the present embodiment, the heat exchanger unit 200 is a device that cools the liquid medium by the refrigerant as described above. When the heat exchanger unit 200 is a device capable of switching between cooling and heating of the liquid medium by the refrigerant, a flow path switching mechanism is provided in the refrigerant circuit 150, as in the refrigerant circuit 50 of the first embodiment.

(2-1-1) compressor

The compressor 130 sucks in the low-pressure refrigerant in the refrigeration cycle returned from the usage-side heat exchanger 110, compresses the refrigerant by a compression mechanism (not shown), and sends the high-pressure refrigerant in the compressed refrigeration cycle to the heat-source-side heat exchanger 140.

The compressor 130 is, for example, a scroll compressor. However, the type of the compressor 130 is not limited to a scroll type, and the compressor 130 may be a screw type, a rotary type, or the like. The compressor 130 may be a variable-capacity compressor or a fixed-capacity compressor, for example.

(2-1-2) Heat Source side Heat exchanger

The heat source-side heat exchanger 140 is a heat exchanger that exchanges heat between the heat source-side liquid medium flowing through the heat source-side heat exchanger 140 and the refrigerant flowing through the heat source-side heat exchanger 140. The type of the heat source-side heat exchanger 340 is not limited, and is, for example, a double-tube heat exchanger. However, the type of the heat source side heat exchanger 340 is not limited to the double-tube heat exchanger, as long as the type of heat exchanger that can be used for the refrigerant and the heat source side liquid medium is appropriately selected.

(2-1-3) expansion mechanism

The expansion mechanism 120 is a mechanism that expands the refrigerant flowing through the second refrigerant pipe 151b to adjust the pressure and flow rate of the refrigerant. In the present embodiment, the expansion mechanism 120 is an electronic expansion valve whose opening degree can be adjusted. The expansion mechanism 120 is not limited to an electronic expansion valve. The expansion mechanism 120 may be an automatic temperature expansion valve having a temperature sensing cylinder, or may be a capillary tube.

(2-1-4) utilization side Heat exchanger

In the use side heat exchanger 110, heat exchange is performed between the refrigerant and the liquid medium. In the present embodiment, the use side heat exchanger 110 is a plate heat exchanger. However, the type of the use-side heat exchanger 110 is not limited to a plate-type heat exchanger, and any type of heat exchanger that can be used for a refrigerant and a liquid medium may be appropriately selected.

The use side heat exchanger 110 is connected to a second refrigerant pipe 151b, a third refrigerant pipe 151c, a first heat exchanger unit liquid medium pipe 166, and a second heat exchanger unit liquid medium pipe 168. The first heat exchanger unit liquid medium pipe 166 is a pipe connecting the liquid medium inlet 162 of the heat exchanger unit 200 and the use side heat exchanger 110. The second heat exchanger unit liquid medium pipe 168 is a pipe connecting the use side heat exchanger 110 and the liquid medium outlet 164 of the heat exchanger unit 200. The liquid medium inlet 162 of the heat exchanger unit 200 is connected to a first communication pipe 422, and the use-side device 410 and the liquid medium inlet 162 of the heat exchanger unit 200 are connected to the first communication pipe 422. The liquid medium inlet 164 of the heat exchanger unit 200 is connected to a second communication pipe 424, and the second communication pipe 424 connects the use-side device 410 and the liquid medium outlet 164 of the heat exchanger unit 200.

When the compressor 130 is operated, the refrigerant flows into the use side heat exchanger 110 from the second refrigerant pipe 151b, flows through a refrigerant passage, not shown, in the use side heat exchanger 110, and flows out into the third refrigerant pipe 151 c. When the pump 160 is operated, the liquid medium flowing out of the utilization-side equipment 410 flows through the first communication pipe 422 toward the liquid medium inlet 162 of the heat exchanger unit 200. The liquid medium flowing into the heat exchanger unit 200 from the liquid medium inlet 162 flows into the use side heat exchanger 110 through the first heat exchanger unit liquid medium pipe 166. The liquid medium exchanges heat with the refrigerant flowing through the refrigerant passage, not shown, of the use side heat exchanger 110 and is cooled when passing through the liquid medium passage, not shown. The liquid medium cooled in the use side heat exchanger 110 flows out to the liquid medium pipe 168 in the second exchanger unit and flows toward the liquid medium outlet 164. The liquid medium flowing from the liquid medium outlet 164 to the outside of the heat exchanger unit 200 flows through the second communication pipe 424 and flows into the use-side device 410.

(2-1-5) outer case

The casing 190 houses various components and various devices of the heat exchanger unit 200 including the compressor 130, the heat source side heat exchanger 140, the expansion mechanism 120, the use side heat exchanger 110, the water collection tray 80, the gas detection sensor 70, and the electric component box 192. The top and side surfaces of the heat exchanger block 200 are enclosed by top and side plates (see fig. 13).

A water collection tray 80 (see fig. 18) is disposed at a lower portion in the housing 190. A heat source side heat exchanger 140 (see fig. 18) is disposed above the water collection tray 80. Further, a use side heat exchanger 110 (see fig. 18) is disposed above the water collection tray 80. The use side heat exchanger 110 is disposed above the heat source side heat exchanger 140 (see fig. 18). The expansion mechanism 120 is disposed on the rear surface side of the casing 190 and above the heat source-side heat exchanger 140 (see fig. 18). The electrical component box 192 is disposed on the front upper side of the housing 190 (see fig. 18). The electric component box 192 is disposed above the heat source side heat exchanger 140 (see fig. 18). The compressor 130 is disposed above the heat source side heat exchanger 140.

At least the back surface of the housing 190 is provided with an opening 191b for maintenance (see fig. 18). Normally, when the heat load processing system 201 is operating, the opening 191b of the casing 190 is closed by the side plate of the casing 190. By removing the side plate of the housing 190 provided in the opening 191b of the housing 190, maintenance and replacement of parts and equipment inside the housing 190 can be performed.

A heat source side liquid medium inlet and a heat source side liquid medium outlet (not shown) to which pipes for the heat source side liquid medium are connected are provided on the back surface of the housing 190. A liquid medium inlet 162 to which the first communication pipe 422 is connected and a liquid medium outlet 164 to which the second communication pipe 424 is connected are provided on the back surface of the housing 190. The connection manner is not limited, and for example, the first communicating pipe 422 is screwed with the liquid medium inlet 162. The connection method is not limited, and for example, the second communication pipe 424 is screwed to the liquid medium outlet 164 to which the second connection pipe 424 is connected. The positions of the heat source-side liquid medium inlet and outlet, the liquid medium inlet 162, and the liquid medium outlet 164 are not limited to the positions shown in the drawings, and may be changed as appropriate.

(2-1-6) Water collecting tray

The water collection tray 80 is disposed at a lower portion of the housing 190. In particular, in the present embodiment, the water collection tray 80 is disposed at the lowermost portion of the housing 190. The water collection tray 80 is disposed below the use side heat exchanger 110. The water collection tray 80 is disposed below the heat source side heat exchanger 140. The water collection tray 80 receives the condensed water generated in the use side heat exchanger 110, the piping through which the liquid medium flows, and the like. In addition, when the heat exchanger unit 200 is installed outdoors, rainwater and the like also flow into the water collection tray 80. In addition, the water collection tray 80 may also have a function as a bottom plate of the housing 190.

Preferably, the water collection tray 80 is disposed below the use side heat exchanger 110, the refrigerant pipe 151, and at least a part of the first heat exchanger unit liquid medium pipe 166 and the second heat exchanger unit liquid medium pipe 168. Preferably, the water collection tray 80 is configured to enclose a majority of the lower portion of the heat exchanger package 200. For example, the water collection tray 80 covers 80% or more of the area of the heat exchanger unit 200 (the bottom area of the casing 190) in a plan view.

Since the structure of the water collection tray 80 of the heat exchanger unit 200 of the second embodiment is the same as that of the water collection tray 80 of the heat exchanger unit 100 of the first embodiment, a description thereof will be omitted herein in order to avoid redundancy.

(2-1-7) gas detecting sensor

Gas detection sensor 70 is a sensor for detecting whether or not gas of the refrigerant is present in inner space Si of water collection tray 80. Preferably, the gas detection sensor 70 is a sensor that has a detection element 72 and detects whether or not the gas of the refrigerant is present at a location where the detection element 72 is disposed. The gas detection sensor 70 is the same sensor as the gas detection sensor 70 of the first embodiment.

As in the first embodiment, detection element 72 of gas detection sensor 70 is disposed in inner space Si of water collection tray 80 located at a lower portion in housing 190. Further, similarly to the first embodiment, the detection element 72 is preferably disposed on the lower end 82ab side of the inclined portion 82a of the bottom plate 82 of the water collection tray 80 (on the rear end side of the bottom plate 82 in the present embodiment). Further, as in the first embodiment, it is preferable that the detection element 72 is disposed in the vicinity of the drain port 86a, and the drain port 86a is a drain port through which water is drained from the internal space Si of the water collection tray 80. Since the detection element 72 is disposed at a position where the refrigerant gas is likely to accumulate as described above, refrigerant leakage detection with high reliability can be performed.

However, as in the first embodiment, the position where the detection element 72 of the gas detection sensor 70 is disposed is not limited to a specific position within the internal space Si of the water collection tray 80. In addition, as in the first embodiment, the position where the detection element 72 of the gas detection sensor 70 is disposed may be a position outside the internal space Si of the water collection tray 80 and where the gas in the internal space Si of the water collection tray 80 can be detected.

Further, as in the first embodiment, the detection element 72 of the gas detection sensor 70 is preferably disposed below an electrical component that may be an ignition source.

In addition, the electrical components that may become ignition sources include electrical components that may generate electric sparks. In the present embodiment, the electric components that may be an ignition source include the electric components 93 such as the electromagnetic switch, the contactor, and the relay housed in the electric component box 192, the inverter board 194 for the compressor 130, the electronic expansion valve as an example of the expansion mechanism 20, and the terminal box 131 of the compressor 130. An electric wire (not shown) for supplying electric power to the motor 130a of the compressor 130 is connected to the terminal box 131 of the compressor 130.

Although not installed in the heat exchanger unit 200 of the present embodiment, in a case where the heat exchanger unit 200 is installed in a cold district, a heater may be disposed in the heat exchanger unit 200. The heater may reach a high temperature to an extent sufficient to constitute an ignition source according to its specification. The electric components that may reach a high temperature to such an extent as to constitute an ignition source are also preferably disposed above the detection element 72 of the gas detection sensor 70.

Further, it is preferable that the electric components that can be an ignition source (in the present embodiment, the electric components 93 such as the electromagnetic switch, the contactor, and the relay housed in the electric component box 192, the inverter board 194 for the compressor 130, the electronic expansion valve as an example of the expansion mechanism 120, and the terminal box 131 of the compressor 130) are disposed at a height position of 300mm or more from the bottom of the housing 190 (see fig. 16 and 17). By disposing the electrical components that may become ignition sources at the height positions, even if the refrigerant leaks, the possibility that the electrical components inside the housing 190 become ignition sources and cause ignition can be reduced.

From the viewpoint of maintenance, the detection element 72 of the gas detection sensor 70 is preferably disposed in a space near the opening 191b for maintenance of the housing 190. The space near the opening 191b is a space that can be reached by the operator through the opening 191 b. For example, the space in the vicinity of the opening 191b is preferably a space in a range touched by a hand from the opening 191b (for example, a space within 50cm from the opening 191 b). When the detection element 72 of the gas detection sensor 70 is disposed at the above position, the detection element 72 can be easily replaced and inspected by removing the side plate of the housing 190 that closes the opening 191 b.

Further, since the detection element 72 of the gas detection sensor 70 detects the refrigerant gas, it is preferable to have the following configuration: even if the condensed water is accumulated in the inner space Si of the water collection tray 80, the detection element 72 is not easily immersed in the water. For example, as in the first embodiment, the heat exchanger unit 200 preferably includes the float 88 disposed in the internal space Si of the water collection tray 80, and the detection element 72 of the gas detection sensor 70 is preferably attached to the upper surface 88a of the float 88 or the side surface 88b of the float 88. Here, to avoid duplicate explanation, the explanation of the float 88 will be omitted.

The detection element 72 of the gas detection sensor 70 may be directly attached to the side wall 84 of the water collection tray 80 and the frame (not shown) of the housing 90. In this case, the detection element 72 of the gas detection sensor 70 is preferably disposed at a position where it is not easily soaked in water, for example, at a position higher than the drain port 86a in the internal space Si of the water collection tray 80 shown by a reference numeral 72a in fig. 18.

The matters described in (2-4-6) of the first embodiment can be applied to the position of the detection element 72 of the gas detection sensor 70, the position of the electrical component that can become an ignition source, and the positional relationship between the detection element 72 of the gas detection sensor 70 and the electrical component that can become an ignition source, without being contradicted.

(2-1-8) electric component case

The electrical component box 192 is a housing that houses various electrical components. The electric component box 192 houses electric components 93 such as a heat exchanger unit side control board 195, a power supply terminal block (not shown), an inverter board 194 for the compressor 130, an electromagnetic switch, a contactor, and a relay (see fig. 14). The electric component 93 may not include all of the electromagnetic switch, the contactor, and the relay, or may include only one of the electromagnetic switch, the contactor, and the relay. The electric components housed in the electric component box 192 are not limited to the illustrated example, and various electric components may be housed as necessary.

The heat exchanger unit-side control board 195 has various circuits, a microcomputer including a CPU and a memory storing a program to be executed by the CPU, and the like.

The heat exchanger unit side control board 195 controls the operations of the respective parts of the heat exchanger unit 200.

The heat exchanger unit-side control board 195 is electrically connected to various devices of the heat exchanger unit 200. The various devices of the heat exchanger block 200 connected to the heat exchanger block-side control board 195 include a compressor 130 and an expansion mechanism 120. Preferably, the heat exchanger block-side control board 195 is capable of sending control signals to the pump 160, the heat source-side pump 520, and the like. The heat exchanger block-side control board 195 is communicably connected to various sensors of the heat source block 200, and receives measurement values from various sensors (not shown). The various sensors that the heat exchanger package 200 has are not limited, and include, for example: temperature sensors provided in the first refrigerant pipe 151a and the third refrigerant pipe 151c and configured to measure the temperature of the refrigerant; a pressure sensor provided in the first refrigerant pipe 151a and measuring the pressure of the refrigerant; and temperature sensors and the like that are provided in the first heat exchanger unit internal liquid medium pipe 166 and the second heat exchanger unit internal liquid medium pipe 168 and measure the temperature of the liquid medium. The heat exchanger block-side control board 195 is communicably connected to the gas detection sensor 70 of the heat exchanger block 200.

The heat exchanger unit-side control board 195 controls the operations of various devices of the heat exchanger unit 200 and the operations of the heat pump 160 and the heat source-side pump 520 in accordance with an operation/stop command provided from an operation device, not shown. The heat exchanger unit-side control board 195 controls the operations of the various devices of the heat exchanger unit 200 such that the liquid refrigerant is cooled to a predetermined target temperature and flows out of the liquid medium outlet 164 of the heat exchanger unit 200. Since the operating principle of the vapor compression refrigerator is well known, the description thereof is omitted here. When the gas detection sensor 70 detects a refrigerant gas leak, the heat exchanger block-side control board 195 controls the devices so that the various devices of the heat exchanger block 200, the pump 160, and the heat source-side pump 520 operate at a predetermined leak time.

(3) Feature(s)

(3-1)

The heat exchanger unit 200 according to the above embodiment performs at least one of cooling and heating of the liquid medium by exchanging heat between the liquid medium sent to the usage-side device 410 and the refrigerant. The heat exchanger unit 200 includes the use-side heat exchanger 110, which is an example of a heat exchanger, the casing 190, the water collection tray 80, and the gas detection sensor 70, which is an example of a first gas detection sensor. In the use side heat exchanger 110, heat is exchanged between the combustible refrigerant and the liquid medium. The housing 190 houses the use side heat exchanger 110. The water collection tray 80 is disposed below the use side heat exchanger 110 and below the housing 190. The water collection tray 80 has a bottom plate 82 and a side wall 84 extending upward from the bottom plate 82. Gas detection sensor 70 detects the presence of gas in the refrigerant in an internal space Si of water collection tray 80, which is located above bottom plate 82 of water collection tray 80 and below the upper end of side wall 84 of water collection tray 80.

Generally, the refrigerant gas is heavier than air, and when the refrigerant leaks, the leaked refrigerant gas moves downward. Therefore, in the present heat exchanger unit 200, the leaked refrigerant gas is likely to accumulate in the water collection tray 80 disposed at the lower portion of the casing 190 and receiving the dew condensation water and the like generated in the piping, the heat exchanger, and the like.

Here, by detecting whether or not the refrigerant gas is present in the internal space Si of the water collection tray 80 in which the leaked refrigerant gas easily accumulates, it is possible to detect the leakage of the refrigerant gas with high reliability.

Preferably, the gas detection sensor 70 has a detection element 72, which is an example of a first detection element, disposed in the internal space Si of the water collection tray 80, and detects whether or not the gas of the refrigerant is present at a location where the detection element 72 is disposed.

Here, by disposing the detection element 72 of the gas detection sensor 70 in the internal space Si of the water collection tray 80 in which leaked refrigerant easily accumulates, leakage detection of refrigerant gas with high reliability can be performed.

(3-2)

In the heat exchanger unit 200 of the above embodiment, the bottom plate 82 of the water collection tray 80 has the inclined portion 82a inclined with respect to the horizontal plane. The detection element 72 is disposed on the lower end side of the inclined portion 82 a.

Here, since the detection element of the gas detection sensor 70 is disposed on the lower end side of the inclined portion 82a where refrigerant gas is likely to collect, refrigerant leakage detection with high reliability can be performed.

(3-3)

In the heat exchanger unit 200 according to the above embodiment, the drain port 86a is provided in at least one of the bottom plate 82 and the side wall 84 of the water collection tray 80, and the drain port 86a is used to drain water in the internal space Si of the water collection tray 80. The detection element 72 is disposed near the drain opening 86 a.

Here, since the detection element 72 of the gas detection sensor 70 is disposed in the vicinity of the drain port 86a of the water collection tray 80 disposed at a position where water is easily discharged, refrigerant leakage detection with high reliability can be performed.

(3-4)

The heat exchanger unit 200 according to the above embodiment includes the float 88 disposed in the internal space Si of the water collection tray 80. The detection element 72 is mounted to the upper surface 88a or the side surface 88b of the float 88.

Here, since the detection element 72 of the gas detection sensor 70 is attached to the upper surface 88a or the side surface 88b of the float 88, the refrigerant leakage can be detected even in a state where water is accumulated in the water collection tray 80.

(3-5)

In the heat exchanger unit 200 of the above embodiment, the opening 191b for maintenance is formed in the housing 190. The detection element 72 is disposed in the space near the opening 191 b.

Here, since the detection element 72 of the gas detection sensor 70 is disposed in the space near the opening 191b for maintenance, the detection element 72 of the gas detection sensor 70 can be easily inspected and replaced.

(4) Modification example

(4-1) modification 2A

The heat exchanger unit 200 of the above embodiment does not have the pump 160 and the heat source side pump 520, but is not limited thereto. The heat exchanger block 200 may also have a pump 160 and/or a heat source side pump 520 disposed within the housing 190.

(4-2) modification 2B

As in modification 1B of the first embodiment, the heat exchanger unit 200 may further include an auxiliary gas detection sensor having a detection element 272 disposed outside the casing 90, in addition to the gas detection sensor 70 disposed in the internal space Si of the water collection tray 80. Detailed description is omitted.

(4-3) modification 2C

In the above embodiment, the liquid medium cooled/heated by the heat exchanger unit 200 circulates in the liquid medium circuit 400, but is not limited thereto. For example, in the case of directly using the cooled/heated liquid medium itself, the liquid medium to be supplied to the use-side device 410 (e.g., a tank) may be directly used without circulating in the liquid medium circuit 400.

Similarly, the heat-source-side liquid medium that exchanges heat with the refrigerant circulates through the heat-source-side liquid medium circuit 50, but the present invention is not limited to this. For example, the heat source side liquid medium may be groundwater or hot waste water. The heat load processing system 201 may not include the heat source device 510, and the heat-source-side liquid medium that has exchanged heat with the refrigerant in the heat-source-side heat exchanger 140 may be discharged as it is.

While the embodiments of the present disclosure have been described above, it should be understood that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as set forth in the appended claims.

Industrial applicability of the invention

The present invention can be widely applied to a heat exchanger unit using a flammable refrigerant, and is useful.

Description of the symbols

10. 110 utilization side heat exchanger (heat exchanger)

60 pump

70 gas detection sensor (first gas detection sensor)

72 detecting element (first detecting element)

80 water collecting tray

82 bottom plate

82a inclined part

Lower end of 82ab inclined part

84 side wall

86a water outlet

88 float

88a upper surface of float

88b sides of the float

90. 190 shell

91b, 191b opening of the housing

100. 200 heat exchanger unit

270 additionally provided with a gas detection sensor (second gas detection sensor)

272 detecting element (second detecting element)

410 utilization side equipment

A1 Pump deployment area

A2 refrigerant side region

Si inner space

Documents of the prior art

Patent document

Patent document 1: international publication No. 2014/97440.